In our study, we did not collect data about the reasons for not prescribing PZA in an initial regimen and co-morbid conditions, including liver disease, were not different between the two groups, but it is possible that attending physicians’ concern about development of ADRs was a factor in omitting PZA in the initial regimen, because patients without PZA were older and had lower serum albumin levels, which might have been indicative of poorer nutritional status, than patients with PZA. This evidence concerns the gene ALB and liver disorder.